CN103713261B - The detection system of a kind of induction motor air-gap eccentric fault and detection method - Google Patents
The detection system of a kind of induction motor air-gap eccentric fault and detection method Download PDFInfo
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- CN103713261B CN103713261B CN201310730913.4A CN201310730913A CN103713261B CN 103713261 B CN103713261 B CN 103713261B CN 201310730913 A CN201310730913 A CN 201310730913A CN 103713261 B CN103713261 B CN 103713261B
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Abstract
The present invention discloses detection system and the detection method of a kind of induction motor air-gap eccentric fault, it is characterized in that: detection system is magnetic field detection coil array of arranging in the following manner on the same circumference face inside stator core: arrange each magnetic field detection ring on axially different position, in magnetic field detection ring, each magnetic field detection coil interval is arranged, between adjacent magnetic field detection ring, magnetic field detection coil quantity is equal, and is on the same parallel lines of axis correspondingly; The terminal box of the lead-in wire access induction motor of magnetic field detection coil; The input terminus of the output terminal access lower computer of terminal box, the input terminus of the output terminal access upper computer of lower computer; By analyzing contrast field signal feature, accurately judge induction motor air-gap eccentric fault type. The present invention can not only detection axis to even bias, also effectively detection axis to uneven bias, and can roughly judge minimal air gap position.
Description
Technical field
The present invention relates to a kind of method utilizing the stator core teeth portion field signal complicated air-gap eccentric fault kind of diagnosis induction motor and eccentric degree, belong to detection technique field.
Background technology
Rotating machine air gap eccentric centre is the phenomenon that between a kind of stator and rotor, radial air gap length is uneven, exists in nearly all motor all more or less. According to uneven distribution characteristics, air gap eccentric centre can be divided into axial even eccentric (static state bias, dynamic bias, mixing bias) and axial uneven bias (oblique bias, arc are eccentric) 2 kinds of base types, as shown in Figure 1. The reason of air gap eccentric centre is caused to have a lot, such as manufacturing and fixing error, bearing wear, shaft bending, nonuniform heating etc. Along with the increase of air gap eccentric centre, strong vibration, noise being caused to increase, bearing accelerates abrasion, even the stator and rotor catastrophe failure such as wiping mutually. Induction motor is widely used, demand big, and some induction motors, for driving important machinery, such as mining diving pump etc., once fault is shut down, not only can bring bigger financial loss, even may cause Serious Accident. Therefore, induction motor carries out fault of eccentricity diagnosis be necessary.
For on-line monitoring and the diagnosis problem of induction motor air-gap eccentric fault, Chinese scholars is done a lot of work. Induction motor utilizes electromagnetic induction effect between stator and rotor, in rotor induced currents to realize the device of energy converting between mechanical. For the distinctive constitutional features of cage-type induction machine, the research of its fault of eccentricity diagnostic techniques has become an independent research point. It is developed so far, mainly launches around stator winding current monitoring and stator and rotor vibration monitoring two broad aspect. Basic thought is that under searching eccentric state, stator winding electric current or machine shell vibrate the distinctive humorous wave component in signal, in this, as the foundation that air gap eccentric centre exists. But, although these methods simple and fast in the extraction of signal, but it is difficult to the multiple over-center type of complete identification, particularly axial uneven eccentricity issues. And with the detection class signal of other phenomenon of the failure such as rotor broken bar seemingly, be sometimes difficult to difference especially. Therefore, how accurately to judge whether induction motor exists air-gap eccentric fault, fault of eccentricity type and eccentric degree comprehensively, it is the research focus of current person skilled, be also the difficult problem faced.
Summary of the invention
For solving the weak point existing for above-mentioned prior art, the present invention provides detection system and the detection method of a kind of induction motor air-gap eccentric fault, by the stator teeth magnetic field of the multiple position of magnetic field detection Coil Detector, analyze contrast signal feature, to can accurately judge induction motor air-gap eccentric fault type.
The present invention is that technical solution problem adopts following technical scheme:
The detection system of a kind of induction motor air-gap eccentric fault, its feature is: described detection system is magnetic field detection coil array of arranging on the same circumference face inside stator core, being distributed as of each magnetic field detection coil in described magnetic field detection coil array: each magnetic field detection ring is set on axially different position, in described magnetic field detection ring, each magnetic field detection coil interval is arranged, between adjacent magnetic field detection ring, magnetic field detection coil quantity is equal, and is on the same parallel lines of axis correspondingly; The lead-in wire of magnetic field detection coil accesses the terminal box of described induction motor; The input terminus of the output terminal access lower computer of described terminal box, the input terminus of the output terminal access upper computer of described lower computer; The number of detection ring is n, is provided with m magnetic field detection coil in each detection ring; M is 4-8, n >=3.
Described magnetic field detection coil is for detecting the motor-field time-domain signal at its position place, and is conveyed into lower computer by terminal box;
Described lower computer is for being converted to motor-field spectrum signal by motor-field time-domain signal, and described motor-field spectrum signal is conveyed into upper computer;
Described upper computer is for showing described motor-field spectrum signal and corresponding position thereof.
Described magnetic field detection coil is arranged on the gullet base of described stator core.
It is provided with in described lower computer the signal amplifying apparatus that described motor-field time-domain signal amplifies.
Based on the detection method of said detecting system, its feature is to carry out as follows:
The motor-field time-domain signal at described its position place of magnetic field detection Coil Detector, and it is conveyed into lower computer by terminal box, described lower computer adopts Fast Fourier Transform (FFT) algorithm that motor-field time-domain signal is converted to motor-field spectrum signal, and described motor-field spectrum signal is conveyed into upper computer;
Described motor-field spectrum signal and position thereof are shown by described upper computer;
Motor-field spectrum signal according to upper computer and position thereof, judge the type of induction motor air-gap eccentric fault as follows:
If the fundamental voltage amplitude at the motor-field spectrum signal at same magnetic field detection ring different positions place and reduces gradually to both sides taking the fundamental voltage amplitude of the motor-field spectrum signal of a certain position as maximum value, then described induction motor occurs static eccentric;
If there is f in the motor-field spectrum signal being positioned on middle magnetic field detection ring1��frSideband, then described induction motor occurs dynamically eccentric; Wherein fr=f1(1-s)/p, f1For supply frequency, s is slip rate, and p is pole logarithm;
If the fundamental voltage amplitude of the motor-field spectrum signal of the magnetic field detection coil being on the same parallel lines of axis and reduces gradually to both sides taking the fundamental voltage amplitude of the motor-field spectrum signal of the magnetic field detection coil being positioned on middle magnetic field detection ring as maximum value, then described induction motor occurs that arc is eccentric;
If be on the same parallel lines of axis the fundamental voltage amplitude of motor-field spectrum signal of magnetic field detection coil be that the fundamental voltage amplitude to be positioned at the motor-field spectrum signal of magnetic field detection coil on outermost magnetic field detection ring as maximum value and reduces gradually to another side, then described induction motor occurs tiltedly eccentric;
If described induction motor occur static eccentric, dynamically eccentric, arc is eccentric and tiltedly eccentric in any two or more, then described induction motor occurs complicated eccentric;
When n is odd number, described in be positioned at middle magnetic field detection ring and refer to (n+1)/2 magnetic field detection ring; When n is even number, described in be positioned at middle magnetic field detection ring and refer to the n-th/2 or n/2+1 magnetic field detection ring.
The useful effect of the present invention is embodied in:
1, the present invention judges induction motor air gap eccentric centre type by the radial magnetic field signal of the multiple position of comparative analysis, can not only detection axis to even bias, also effectively detection axis to uneven bias, and can roughly judge minimal air gap position;
2, accurate and effective of the present invention, can make up and be difficult to the deficiency of detection axis to bias based on the diagnostic techniques of stator electric current and vibration performance, for safe operation and the trouble diagnosis of induction motor provides important reference.
Accompanying drawing explanation
Fig. 1 is induction motor air gap eccentric centre type schematic diagram;
Fig. 2 is whole detection equipment schematic diagram of the present invention;
Fig. 3 is magnetic field detection coil distribution schematic diagram;
Fig. 4 is magnetic field detection coil scheme of installation;
Number in the figure: 1 is induction motor, 2 is lower computer, and 3 is upper computer, and 4 is terminal box, and 5 is magnetic field detection coil, and 6 is the lead-in wire of magnetic field detection coil, and 7 is stator core.
Embodiment
As shown in Figures 2 and 3, the detection system of the present embodiment induction motor air-gap eccentric fault is magnetic field detection coil array of arranging on the same circumference face inside stator core 7, being distributed as of each magnetic field detection coil 5 in magnetic field detection coil array: each magnetic field detection ring is set on axially different position, in magnetic field detection ring, each magnetic field detection coil interval is arranged, between adjacent magnetic field detection ring, magnetic field detection coil quantity is equal, and is on the same parallel lines of axis correspondingly; The terminal box 4 of the lead-in wire 6 described induction motor of access of magnetic field detection coil; The input terminus of the output terminal access lower computer 2 of terminal box 4, the input terminus of the output terminal access upper computer 3 of lower computer 2; The number of detection ring is n, is provided with m magnetic field detection coil in each detection ring. As required, m is traditionally arranged to be 4-8, n >=3. For three-phase cage induction machine, by 50Hz three-phase symmetrical ac power supply, it is 3 that m is set to 6, n, arranges 18 magnetic field detection coils altogether.
Magnetic field detection coil 5 is for detecting the motor-field time-domain signal at its position place, and is conveyed into lower computer 2 by terminal box 4; Lower computer 2 is for being converted to motor-field spectrum signal by motor-field time-domain signal, and motor-field spectrum signal is conveyed into upper computer 3; Upper computer 3 is for showing motor-field spectrum signal and corresponding position thereof.
As shown in Figure 4, in concrete enforcement, magnetic field detection coil 5 is arranged on the gullet base of stator core 7, and the lead-in wire 6 of magnetic field detection coil is positioned at the bottom land of stator core 7 and is connected into terminal box 4. By cutting out part siliconized plate teeth portion, leave two narrow grooves and magnetic field detection coil is embedded at trench bottom. The lead-in wire of magnetic field detection coil is laid along stator groove, stretches out from End zone of stator core and leads to into terminal box. For induction motor, detection coil can be controlled in about 10mm along the axial length. If due to magnetic field detection coil, to install space sufficient and decrease the number of turn of detection coil, and then causes the magnetic field time-domain signal obtained faint, then can arrange in lower computer the signal amplifying apparatus that motor-field time-domain signal amplifies.
The detection method of the present embodiment carries out as follows:
The motor-field time-domain signal at its position place of magnetic field detection Coil Detector, and it is conveyed into lower computer by terminal box, lower computer adopts Fast Fourier Transform (FFT) algorithm that motor-field time-domain signal is converted to motor-field spectrum signal, and motor-field spectrum signal is conveyed into upper computer; Motor-field spectrum signal and position thereof are shown by upper computer;
Motor-field spectrum signal according to upper computer and position thereof, judge the type of induction motor air-gap eccentric fault as follows:
If the fundamental voltage amplitude at the motor-field spectrum signal at same magnetic field detection ring different positions place and reduces gradually to both sides taking the fundamental voltage amplitude of the motor-field spectrum signal of a certain position as maximum value, then induction motor occurs static eccentric;
If there is f in the motor-field spectrum signal being positioned on middle magnetic field detection ring1��frSideband, then induction motor occurs dynamically eccentric; Wherein fr=f1(1-s)/p, f1For supply frequency, s is slip rate, and p is pole logarithm;
If the fundamental voltage amplitude of the motor-field spectrum signal of the magnetic field detection coil being on the same parallel lines of axis and reduces gradually to both sides taking the fundamental voltage amplitude of the motor-field spectrum signal of the magnetic field detection coil being positioned on middle magnetic field detection ring as maximum value, then induction motor occurs that arc is eccentric;
If be on the same parallel lines of axis the fundamental voltage amplitude of motor-field spectrum signal of magnetic field detection coil be that the fundamental voltage amplitude to be positioned at the motor-field spectrum signal of magnetic field detection coil on outermost magnetic field detection ring as maximum value and reduces gradually to another side, then induction motor occurs tiltedly eccentric;
If induction motor occur static eccentric, dynamically eccentric, arc is eccentric and tiltedly eccentric in any two or more, then induction motor occurs complicated eccentric;
When n is even number, described in be positioned at middle magnetic field detection ring and refer to the n-th/2 or n/2+1 magnetic field detection ring.
Claims (5)
1. the detection system of an induction motor air-gap eccentric fault, it is characterized in that: described detection system is magnetic field detection coil array of arranging on the same circumference face inside stator core, being distributed as of each magnetic field detection coil in described magnetic field detection coil array: each magnetic field detection ring is set on axially different position, in described magnetic field detection ring, each magnetic field detection coil interval is arranged, between adjacent magnetic field detection ring, magnetic field detection coil quantity is equal, and is on the same parallel lines of axis correspondingly; The lead-in wire of magnetic field detection coil accesses the terminal box of described induction motor; The input terminus of the output terminal access lower computer of described terminal box, the input terminus of the output terminal access upper computer of described lower computer; The number of detection ring is n, is provided with m magnetic field detection coil in each detection ring; M is 4-8, n >=3.
2. the detection system of induction motor air-gap eccentric fault according to claim 1, it is characterised in that: described magnetic field detection coil is for detecting the motor-field time-domain signal at its position place, and is conveyed into lower computer by terminal box;
Described lower computer is for being converted to motor-field spectrum signal by motor-field time-domain signal, and described motor-field spectrum signal is conveyed into upper computer;
Described upper computer is for showing described motor-field spectrum signal and corresponding position thereof.
3. the detection system of induction motor air-gap eccentric fault according to claim 1 and 2, it is characterised in that: described magnetic field detection coil is arranged on the gullet base of described stator core.
4. the detection system of induction motor air-gap eccentric fault according to claim 1 and 2, it is characterised in that:
It is provided with in described lower computer the signal amplifying apparatus that described motor-field time-domain signal amplifies.
5. the detection method based on detection system described in claim 1, it is characterised in that carry out as follows:
The motor-field time-domain signal at described its position place of magnetic field detection Coil Detector, and it is conveyed into lower computer by terminal box, described lower computer adopts Fast Fourier Transform (FFT) algorithm that motor-field time-domain signal is converted to motor-field spectrum signal, and described motor-field spectrum signal is conveyed into upper computer;
Described motor-field spectrum signal and position thereof are shown by described upper computer;
Motor-field spectrum signal according to upper computer and position thereof, judge the type of induction motor air-gap eccentric fault as follows:
If the fundamental voltage amplitude at the motor-field spectrum signal at same magnetic field detection ring different positions place and reduces gradually to both sides taking the fundamental voltage amplitude of the motor-field spectrum signal of a certain position as maximum value, then described induction motor occurs static eccentric;
If there is f in the motor-field spectrum signal being positioned on middle magnetic field detection ring1��frSideband, then described induction motor occurs dynamically eccentric; Wherein fr=f1(1-s)/p, f1For supply frequency, s is slip rate, and p is pole logarithm;
If the fundamental voltage amplitude of the motor-field spectrum signal of the magnetic field detection coil being on the same parallel lines of axis and reduces gradually to both sides taking the fundamental voltage amplitude of the motor-field spectrum signal of the magnetic field detection coil being positioned on middle magnetic field detection ring as maximum value, then described induction motor occurs that arc is eccentric;
If be on the same parallel lines of axis the fundamental voltage amplitude of motor-field spectrum signal of magnetic field detection coil be that the fundamental voltage amplitude to be positioned at the motor-field spectrum signal of magnetic field detection coil on outermost magnetic field detection ring as maximum value and reduces gradually to another side, then described induction motor occurs tiltedly eccentric;
If described induction motor occur static eccentric, dynamically eccentric, arc is eccentric and tiltedly eccentric in any two or more, then described induction motor occurs complicated eccentric;
When n is odd number, described in be positioned at middle magnetic field detection ring and refer to (n+1)/2 magnetic field detection ring; When n is even number, described in be positioned at middle magnetic field detection ring and refer to the n-th/2 or n/2+1 magnetic field detection ring.
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| CN104124844B (en) * | 2014-07-08 | 2016-08-17 | 扬州大学 | Eliminate station and tilt the method that the vertical unit motor caused installs air gap inequality |
| CN104614673B (en) * | 2015-02-25 | 2017-12-05 | 珠海派诺科技股份有限公司 | A kind of motor gas-gap fault of eccentricity diagnostic method based on fuzzy reasoning |
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| CN110531259B (en) * | 2019-08-12 | 2020-08-18 | 西安交通大学 | Electrical fault diagnosis method for induction motor based on magnetic leakage signal |
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| CN114460465A (en) * | 2022-04-08 | 2022-05-10 | 华中科技大学 | Method and system for judging eccentric fault of permanent magnet motor |
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